The Southern Cross

Дата канвертавання24.04.2016
Памер49.12 Kb.
“The Southern Cross”



We hope you find this month’s newsletter informative and interesting. We welcome the following new members: Jay Botha, Andre de Villiers, Mark Heistein, Fanie Lombard, Grant Mclachlan and Stephen Smuts.
2012 membership fees A reminder to those who have not already paid that the fees for this year are due. They are: Individuals: R120, second family member, students and children: R70. They can be paid in cash at the monthly meetings, by cheque made out to Hermanus Astronomy Centre and mailed to Treasurer Pierre de Villiers, P O Box 267, Hermanus, or online. The ABSA bank details are as follows:

Account name – Hermanus Astronomy Centre

Account number – 9230163786

Branch code – 632005.

Reference – your name + ‘membership’
Trip to Cape Town Places are still available for this event, scheduled for Saturday 25 February. It includes a visit to the firing of the noon gun on Signal Hill, lunch and viewing of a show at the Planetarium in the Gardens, a tour of the Observatory, and, after an evening meal at the nearby River Club,, sky-gazing through the recently renovated McLean telescope. Please contact John Saunders at or on 028 314 0543 to reserve a place.
Depending on member interest, visits to the Cederburg observatory in April/May or September/October and/or Sutherland in September/October are possible this year. If you are interested in either one or both, please let John Saunders know at or on 028 314 0543.
2012 Sky Guide Copies may still be available, at a price of R35. If you are interested, please contact John Saunders at or on 028 314 0543.

Lepus (the Hare) lies under the feet of the hunter, Orion (upside down when viewed from the southern hemisphere). Although the hare is not a figure in Greek mythology, it is one of the 48 constellations named by Ptolemy in the 2nd century. Only the 51st largest constellation, with no particular features, its fame arises from its proximity to its impressive neighbours. It represents a hare being pursued by the larger of Orion’s dogs, Canis Major. On a clear night, and with an active imagination, it is possible to see the quadrilateral formed by its four brightest stars as the hare’s body, and the two bright stars on the one side forming the ears.


Monthly centre meeting The focus of Dr David Gilbank’s presentation on 26 January was on the work he and others are doing on the nature of galaxy clusters, not only deepening knowledge and understanding of these related structures, but on what they tell us about the characteristics and growth of the early universe. Using excellent illustrations, he explained how, although the Hubble ultra-deep field identified thousands of previously unknown galaxies, it had only a tiny field of view. This has led to the development of a series of both land and space-based large survey projects designed to map deep fields across large areas of the sky. Work he and colleagues have undertaken on optical and spectrographic observations made using telescopes in Hawaii and Chile have led to an alternative classification of galaxies, and the clusters they tend to exist in, by colour (red for inactive, blue for active in star formation) rather than by shape eg spiral, elliptical. This approach, and use of data from wide fields which have identified more than 30,000 ‘new’ clusters, have enabled the researchers to learn more about the nature of these clusters and how they change over time. Dr Gilbank finished by explaining how, during his current employment at the SAAO in Cape Town, he is using data from SALT to study specific areas identified by the larger surveys as being of particular interest.
Interest groups Cosmology The review of some of the DVDs in the ‘Cosmology’ series continues to be popular with both members and visitors. On 9 January, 21 people attended the lecture on ‘Measuring distances’ Lecture 6), and, on 23 January, 26 attended the lecture titled ‘Dark matter and dark energy – 96%!’ (Lecture 9). Both presentations were followed by questions and discussion on the topics and others arising from them.
Beginners astronomy 35 people (18 members, 17 visitors) attended the meeting on 16 January. The new format of a DVD from the Introduction to astronomy’ series by Prof. Alex Filipenko of the University of California followed by questions and star-gazing was very successful.
Other activities Sidewalk astronomy Those who attended the evens on 27 and 28 January were treated to views of and information about the Moon, Venus, Jupiter and the Galilean moons, Orion, Eta Carinae, the Southern Cross, and the Jewel Box.

Monthly centre meeting This will take place on 23 February at 7 pm at SANSA. It is the Centre’s Annual General Meeting, which will be followed by a presentation on the planned Astronomy Education Centre and Observatory.

Weather permitting, there will be an opportunity for stargazing from the SANSA car park. An entrance fee of R20 will be charged per person for non-members and R10 for children & students.
Interest group meetings The Cosmology group meets on the first and third Monday of every month at 7 pm at SANSA. At each meeting, a ‘Cosmology’ DVD lecture will be re-screened, followed by discussion led by a group member. Lectures for consideration in February are: 6 February: ‘Cosmic expansion: falling outward’ (Lecture 12), and 20 February: ‘The cosmic microwave background’ (Lecture 13).
Visitors who attend for one evening are welcome for free, but will need to join the Centre if they wish to attend further meetings. For further information on these meetings, or any of the group’s activities, please contact Pierre Hugo at
Beginners astronomy Meetings take place monthly on the second Monday of the month at 7 pm at SANSA. They will consist of one or two DVD lectures followed by questions and, weather-permitting, star gazing from the car park. At this month’s meeting on 13 February, two DVD’s from the ‘Introduction to astronomy” series will be presented: ‘Our sky through binoculars and telescopes’ and ‘The celestial sphere’. This will be followed by a short presentation by Johan Retief on ‘Interpreting star maps on the plane of the observer’s horizon’ and a hand’s on explanation of different kinds of telescopes. Weather permitting, there will also be star-gazing. For further information, please contact Pierre de Villiers at

Visits to observatories See details in the introduction.

These take place at 7 pm at SANSA (formerly HMO).

23 February AGM

22 March Topic: TBA Presenter: Kechil Kirkham, ASSA, Cape Centre.

26 April ‘The cosmic time machine’ by Michellle Knights, UCT

24 May ‘The Hertzsprung-Russell diagram made easy’ by Pierre de

Villiers, committee member

21 June Topic: TBA Presenter: Johan Retief, Centre member

19 July ‘Optical instrumentation at SALT‘ by Lisa Crause, SAAO, CT

23 August ‘Topic: TBA Presenter: Case Rijsidjk

20 September ‘Tracking satellites and astronomical objects’ by Greg

Roberts, amateur astronomer and satellite chaser

18 October Topic and presenter: TBA

15 November ‘The Herschels – a family of astronomers’ by John Saunders

14 December. Christmas party


As part of the ongoing planning process, Overstrand Municipality has sent out the HAC response to those who submitted formal objects. A report including the objections and the response will be submitted to the full Council for consideration in due course. More detail on the preparatory work being done will be presented at the AGM.

We again thank those who have contributed to the Friends of the Observatory campaign. The funds received have been central in continuing with the planning process requirements and the campaign will continue to welcome any size donation, small or large. Contributions can take the form of cash, cheque or online transfer, either as one payment, or on a monthly payment basis. The ABSA bank details are as follows:

Account name – Hermanus Astronomy Centre

Account number – 9230163786

Branch code – 632005.

If you make an online donation, please include the word ‘pledge’, and your name, unless you wish to remain anonymous.
For further information, please contact John Saunders on 028 314 0543 or at

Kepler Discovers a Tiny Solar System 11 January 2012: Astronomers using data from NASA's Kepler mission and ground-based telescopes have discovered the three smallest planets yet detected orbiting a star beyond our Sun. More like Jupiter and its moons than a start and its planets, a single star, called KOI-961, hosts the three smallest exoplanets known so far to orbit a star other than the Sun. They are 0.78, 0.73 and 0.57 times the radius of Earth, the smallest being about the size of Mars.
All three planets are thought to be rocky like Earth, but orbit close to their star. That makes them too hot to be in the habitable zone, which is the region where liquid water could exist. Of the more than 700 planets confirmed to orbit other stars -- called exoplanets -- only a handful are known to be rocky. "Astronomers are just beginning to confirm thousands of planet candidates uncovered by Kepler so far," said Doug Hudgins, Kepler program scientist at NASA Headquarters in Washington." Finding one as small as Mars is amazing, and hints that there may be a bounty of rocky planets all around us."
Extract from NASA news bulletin.
Hubble does it again 10 Jan 2012: In a sky survey made in near-infrared light Hubble has spotted five galaxies clustered together. They are so distant that their light has taken 13.1 billion years to reach us. These galaxies are among the brightest galaxies at that early stage of the Universe’s history. They are also very young: we are seeing them just 600 million years after the Universe’s birth in the Big Bang.

In a sky survey made in near-infrared light, Hubble has spotted five galaxies clustered together. They are so distant that their light has taken 13.1 billion years to reach us. These galaxies are among the brightest galaxies at that early stage of the Universe’s history. They are also very young: we are seeing them just 600 million years after the Universe’s birth in the Big Bang.

“These galaxies formed during the earliest stages of galaxy assembly, when galaxies had just started to cluster together,” says the study’s leader, Michele Trenti (University of Cambridge, UK and University of Colorado at Boulder, USA). “The result confirms our theoretical understanding of the buildup of galaxy clusters. And Hubble is just powerful enough to find the first examples of them at this distance.”
Extract from Hubble ESA news bulletin
Asteroid Eros flies by Discovered in 1898, Eros is the second biggest ‘near-earth’ asteroid known (the biggest being 1036 Asteroid Ganymede). In January 1975, Eros made an historically close flyby observed at magnitude 7.0. In 2000/2001 Eros was again in the news when NASA'S Near-Earth Shoemaker space probe went into orbit around this 34 x 11 x 11 km odd shaped piece of rock and then descended to its surface. A remarkable feat of pinpoint navigation over thousands of kilometres of space flight.

And on 31 January, Eros was 0.18 AU from Earth as it makes another ‘near-earth’ flyby. ‘Near’ is of course relative. (0.18 AU is 70 times the Moon's distance from Earth). It was visible at magnitude 8.6 close to Delta Sextans in the Eastern sky at about 22h00.

Source: NASA bulletins.
Another Hubble milestone 3 February 2012:

The NASA/ESA Hubble Space Telescope has taken a picture of the barred spiral galaxy NGC 1073, which is found in the constellation of Cetus (The Sea Monster). Our own galaxy, the Milky Way, is thought to be a similar barred spiral, and the study of galaxies such as NGC 1073 can help astronomers learn more about our celestial home.

Credit: NASA & ESA

Mission to land on a comet 2 February 2012: Europe’s Rosetta spacecraft is en route to intercept a comet and to make history. In 2014, Rosetta will enter orbit around comet 67P/Churyumov-Gerasimenko, and land a probe on it. Two firsts.

Rosetta’s goal is to learn the primordial story a comet tells as it gloriously falls to pieces. Comets are primitive leftovers from our solar system's 'construction' about 4.5 billion years ago. Because they spend much of their time in the deep freeze of the outer solar system, comets are well preserved — a gold mine for astronomers who want to know what conditions were like back ‘in the beginning’.

As their elongated orbits swing them closer to the Sun, comets transform into the most breathtaking bodies in the night sky. A European Space Agency mission launched in 2004 with US instruments on board, Rosetta will have a front-row seat for the metamorphosis.

What we know of comets so far comes from a handful of flyby missions. "In some ways, a flyby is just a tantalizing glimpse of a comet at one stage in its evolution," says Claudia Alexander, project scientist for the US Rosetta Project at the Jet Propulsion Laboratory, California. "Rosetta is different. It will orbit 67P for 17 months. We'll see this comet evolve right before our eyes as we accompany it toward the sun and back out again." Fierce solar heat will have a profound effect on Rosetta’s target. "We'll watch the comet start as just a little nugget in space and then become something poetic and beautiful, trailing a vast tail."

At the moment, Rosetta is "resting up" for the challenges ahead. It's hibernating, engaged in its high-speed chase while fast asleep. Reveille is on or around New Year's Day 2014, when the spacecraft begins a months-long program of self-checkups.

If all goes well, in August of the same year, Rosetta will enter orbit around 67P's nucleus and begin scanning its surface for a landing site. Once a site is chosen, the spacecraft will descend as low as 1 km to deploy the lander. The lander’s name is “Philae” after an island in the Nile, the site of an obelisk that helped decipher — you guessed it — the Rosetta Stone.

Touchdown is scheduled for November 2014, when Philae will make the first ever controlled landing on a comet's nucleus. "When we land, the comet could already be active!" says Alexander. Because a comet has little gravity, the lander will anchor itself with harpoons. “The feet may drill into something crunchy like permafrost, or maybe into something rock solid,” she speculates.

Once it is fastened, the lander will commence an unprecedented first-hand study of a comet’s nucleus. Among other things, it will gather samples for examination by automatic onboard microscopes and take panoramic images of the comet’s terrain from ground level. Meanwhile, orbiting overhead, the Rosetta spacecraft will be busy, too. Onboard sensors will map the comet’s surface and magnetic field, monitor its erupting jets and geysers, measure outflow rates, and much more. Together, the orbiter and lander will build up the first 3D picture of the layers and pockets under the surface of a comet.

The results should tell quite a story indeed.

Author:Dauna Coulter | Editor: Dr. Tony Phillips | Credit: Science@NASA


Space exploration. Part 9: Reaching for the Moon: the Apollo programme (Part 1)

Earth rise from Moon Command module

orbit - Apollo 8 seen from lunar

Module - Apollo 10

Although conceived in 1960 as a follow-up to Project Mercury, it was not until Kennedy’s famous public address to a Joint Session of Congress in May 1961 that the Apollo programme really began. One of Kennedy’s 1960 election promises had been to establish American superiority over the Soviets. However, it took Gagarin’s successful launch into space in April 1961 to motivate Kennedy to openly support and fund the Apollo programme. Kennedy’s desire for the USA of ‘landing a man on the Moon and returning him safely to the Earth’ launched a very ambitious goal at a time when only one American had flown in space and NASA had not yet even put a man into Earth orbit. Reaching the ultimate goal of a manned Moon landing within a decade required probably the greatest and fastest peacetime advances in technological creativity and engineering, and the biggest peacetime commitment of resources by any one nation ($25 billion and nearly half a million people).
It was achievements during the 1961–1975 duration of the Apollo programme which put the US first in the Space Race. It achieved a number of world ‘firsts’, including first mission beyond low Earth orbit (Apollo 8), first manned spacecraft to orbit and return to Earth from another celestial body (Apollo 8), and first to land a man on the Moon (Apollo 11). The programme also included several American ‘firsts’, including first 3-manned US space mission (Apollo 7), first US space station (Skylab 1), and first docking between manned spacecraft (Apollo 9). The final Apollo mission also proved, so far, to be the last manned mission beyond Earth orbit (Apollo 17).
In addition to these firsts, technological advances within the Apollo programme have also significantly led developments in avionics, computers, telecommunications, medicine e.g. cochlear implants, transportation, environmental resources e.g. solar energy, public safety e.g. fire safety equipment, and other areas of life e.g. clothing fabrics, baby foods, cell phones, microwave ovens, sunscreen, memory foam, which are central to current lifestyles.
Named after the Greek god of light and music, unlike the Mercury spacecraft which could only support one astronaut on Earth orbit missions, the Apollo spacecraft was able to carry three astronauts on return journeys to the Moon. From a number of possible designs, the Apollo spacecraft eventually involved a modular design made up of a command module, a service module and a lunar module. All the missions used variations of the Saturn rocket.
The programme consisted of 25 un-manned and 11 manned missions, the latter taking place between October 1968 and December 1972. Of all the 36 Apollo missions, only three failed, one at the cost of three lives (the fatal Apollo 1 launch pad fire in 1967) and another at potential human cost: (the oxygen tank rupture on Apollo 13 in 1970). The mission designated Apollo 1 was not a planned manned mission, but a test which failed. Because it involved human fatalities, it was given an Apollo label. In fact, the first scheduled manned flight was Apollo 7. The purpose of the un-manned missions was to test the structural integrity of the new spacecraft, and different components, including rockets, launch escape system, and the lunar module. One of the unmanned missions also launched Skylab, the first US space station, in 1973.
The 1967 tragedy of Apollo 1 had been anticipated by the 3 astronauts several months before the fire, when they had expressed concerns about fire hazards and other problems. Investigation of the disaster did not officially identify the ignition source, but did list a wide range of lethal design and construction flaws in the early command module. These included use of a pure oxygen atmosphere, sub-standard wiring and plumbing, flammable materials in the cabin, electro-static discharge when the nylon flight pressure suits and flight seats were moved against each other, and inability of the hatch to open against high cabin pressures. Correction of the numerous faults delayed launch of the manned phase of the project by almost 2 years.
Apollo 7 was an 11-day Earth orbital mission intended to test the spacecraft’s life support, propulsion and control systems. Although the mission met its objectives, tensions between the astronauts and staff at Mission Control led to rejection of the crew members for later missions. The following three missions involved Moon orbits. Delays in completion of the lunar module meant that Apollo 8 consisted only of a command-service module. However, it had the distinction of being the first human spaceflight to leave Earth orbit, and enter and leave another celestial body’s orbit. The astronauts were also the first humans to directly see the far side of the Moon. The Christmas Eve television transmission from the spacecraft was, then, the most watched TV programme ever.
The Apollo 9 and 10 missions were extensions of Apollo 8, leading inexorably to the Moon landing of Apollo 11. In March 1969, Apollo 9, the first test of the complete Apollo spacecraft, spent ten days in Earth orbit, the crew performing the first manned flight of a lunar module (LM), first docking and extraction of an LM, a two-man extra-vehicular activity (EVA) during which the new Apollo spacesuit (the first to have its own life support system) was used, and the second docking of two manned spacecraft (The Soviets had achieved this first two months earlier). The May 1969 Apollo 10 mission was a ‘dry run’ for Apollo 11, testing all the components and procedures of a Moon landing, including docking and undocking of the LM, without actually making a landing. The spacecraft orbited the Moon for 2½ days, the LM coming within 15.6 km of the lunar surface during testing. All the manned Apollo missions had an on-board TV camera, but Apollo 10 was the first to make live colour TV broadcasts from space.
* Programmes highlighted in bold* are covered in other parts of this series


For more information on the Hermanus Astronomy Centre and its activities, visit our website at

John Saunders (Chairman) 028 314 0543

Steve Kleyn (Technical Advisor) 028 312 2802

Pierre de Villiers (Treasurer) 028 313 0109

Irene Saunders (Secretary) 028 314 0543

Jenny Morris (Newsletter editor) 071 350 5560

Derek Duckitt (Website editor) 082 414 4024

Johan Retief (Monthly sky maps) 028 315 1132

Peter Harvey (Membership secretary) 028 316 3486

Non-committee members with roles:

Pierre Hugo (Cosmology interest group co-ordinator) 028 312 1639

База данных защищена авторским правом © 2016
звярнуцца да адміністрацыі

    Галоўная старонка